A pressure bulkhead belongs to the internal structures of an aircraft fuselage and is used for ensuring a pressure tight interior, e.g. in the tail section of said aircraft. The bulkhead consists generally of rigid shells, e.g. with a single or double curvature, made of metal or composite materials, often reinforced by so called stiffeners.
The main disadvantages of the existing solutions of a pressure bulkhead are the following: the weight increment of the structure necessary for the prevention of static instabilities; the difficult manufacturing processes for both the metal and the composite materials solutions; the use of expensive materials and/or processes; and the difficult maintenance of the structures next to the pressure bulkhead.
With regard to the weight increment the main structural problem is the static instability caused by shear and compression forces. These instabilities arise in correspondence of load states as the lateral maneuvers with high twisting moments (high shear stresses), and in correspondence of negative pressure gradients (high compression stresses), such as an eventual rapid loss of altitude of the aircraft. For these reasons, a thickness increase of the shell of a rigid pressure bulkhead is necessary and in order to save weight, the adoption of stiffeners in the radial direction as well as sometimes in the circumferential direction may be mandatory.
Regarding the difficult manufacturing due to the presence of the stiffeners and due to the double curvature of the above mentioned bulkheads, the manufacturing process results in a very complex and expensive task.
In case of use of expensive materials and/or processes, composite materials are often advantageous because of their ability to save weight and to fit a shape having a double curvature, avoiding the high number of rivets needed for a metal solution. Such materials are as well expensive as their manufacturing processes, especially in the case of composite sandwich stiffeners.
With regard to the difficult maintenance, due to the curvature adopted and the related space occupation, it results in a difficult access to the structure in the back of the pressure bulkhead and a difficult cleaning of the areas close to the attachment of the bulkhead to the correspondent frame.
Document EP 0 217 117 A1 describes a pressure bulkhead with a curvature provided with a safety support assembly made of a belt network. The belts are fastened to the bulkhead after having fastened the same.
There is a need to reduce the weight, manufacturing time, manufacturing costs and to provide easier maintenance of a pressure bulkhead.